Frequency Modulated Circular Dichroism Spectroscopy: Application to ICN Photolysis
CN photofragments produced in the 248 nm photolysis of ICN are characterised by frequency-modulated absorption spectroscopy in the red A{sup 2}{pi} {l_arrow} X{sup 2}{Sigma}{sup +} system. A range of high rotational states in both v = 0 and v = 1 were selected to isolate only those dissociation channels including coincident ground state I({sup 2}P{sub 3/2}). Velocity-resolved alignment and orientation parameters are determined from the observed Doppler profiles. The alignment measurements for both v = 0 and v = 1 levels are very similar, and consistent with dissociation occurring via three distinct pathways, beginning with simultaneous excitation of the 4A{prime}({sup 3}{pi}{sub 0+}), 5A{prime}({sup 1}{pi}{sub 1}) and 5A{double_prime}({sup 1}{pi}{sub 1}) surfaces. While the incoherent alignment parameters for both v = 0 and v = 1 products are similar, the corresponding coherent orientation parameters are markedly different. CN (v = 0, N) exhibits a large positive orientation, whereas all rotational states probed in v = 1 show a much smaller orientation. This is consistent with the previously observed change in the sign of the coherent orientation parameter between v = 0 and v = 2.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 985820
- Report Number(s):
- BNL-90878-2010-JA; MOPHAM; R&D Project: CO-006; KC0301020; TRN: US201016%%2268
- Journal Information:
- Molecular Physics, Vol. 108, Issue 7-9; ISSN 0026-8976
- Country of Publication:
- United States
- Language:
- English
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